With continuous development of wireless sensor network technology, the wireless sensor network is widely used in state monitoring of mechanized equipment due to the advantages of small in size, easy and convenient to be arranged, free from wiring, convenient for maintaining and the like. For example, patent application CN101413834 proposes to apply the monitoring wireless sensor node to stress field detection of the roller of an elevator, however, in actual application, since the wireless sensor node disposed on the elevating roller web would move along with the detected object, the wireless sensor node can only be powered by a dry battery or an accumulator. Moreover, the sensor node consumes a larger amount of energy with respect to the battery, which causes frequent changing of batteries, which greatly restricts the development of the online monitoring system of the wireless sensor network, and reduces reliability of the system. Since changing the batteries requires to be done after turning off the machine, smooth manufacturing procedure is influenced. In order to solve the problem of supplying energy to the sensor node, it is proposed to use a backup power supply. When the electric quantity of the battery on the node runs out, it automatically switches to other power sources for supplying power. However, too many batteries would increase the volume of the node, and is not convenient for installation. It is also proposed to use the energy generated by air flow during the rotation procedure of the roller web to supply power to the node, however, the energy collected in this way is a little, so a relatively long period of time is required to satisfy the electricity utilization requirements of the node. Moreover, during a high-speed rotation occasion, the collecting device would be hard to install due to large centripetal force and air resistance.